Light-Emitting Diode (LED) with characteristics of high efficiency and long lifespan has been broadly applied in products, such as indicator box, illumination board, backlight module and advertising lamp board. Since the light-emitting diode is a point light source, conversion of the light-emitting diode into a plane light source rests in how to convert the point light source into a uniform planar light source. Mostly, the light-emitting diode is arranged in array to provide the required plane light source, for example, with a direct-type design or a side-type design. The light provided by the light-emitting diode that is arranged in array may be uniformed through stacking lens, light guide plate, diffusive film, brightness enhancement film (BEF), micro-lens film, and other optical films.
Generally, a small number of the light-emitting diodes are used in plane light source with the side-type design, and the light provided by the light-emitting diodes is converted into the plane light source through a light guide plate. Thickness of the plane light source with the side-type design is relatively thin. The plane light source with the side-type design is mainly applied to mobile phone, personal digital assistant (PDA), global positioning system (GPS), etc.
Generally, a large number of light-emitting diodes are used in plane light source with the direct-type design so as to provide an illumination area with a light utilization rate up to approximately 90%. The thickness of the plane light source with the direct-type design is thicker.
However, neither the plane light source with the side-type design nor the plane light source with the direct-type design has a characteristic of flexibility. Therefore, how to provide the plane light source with flexibility and favorable light-emitting uniformity is, in fact, a focus in the current stage of development.